海上油田三次采油用聚合物对采出液油水分离特性的影响评价

Evaluation of the Influence of Offshore Oilfield Tertiary Oil Recovery Polymer on the Oil-Water Separation Characteristic of Produced Liquid

聚合物驱是提高采收率的重要手段之一,然而由聚合物返排导致的油水分离难题至今仍未彻底解决.以渤海某河流相油田为例,从系统工程的角度出发,在驱油用聚合物选型阶段即考虑聚合物对后续采出液处理的影响,研究不同类型的聚合物对模拟原油采出液油水分离的影响规律.结果表明:具有表面活性的聚合物可以大大增加油田采出水的处理难度,不具有表面活性的聚合物虽然也会提高采出水的稳定性,但程度较低;聚合物对油水分离速度影响较小,但可严重降低油水的分离程度,且不具有表面活性的聚合物对油水分离程度的影响相对较小.基于以上结果,建议优先选择线性聚合物作为驱油用聚合物.

Polymer flooding is an important method to enhance oil recovery. However,the oil-wa- ter separation problem caused by polymer flow back is still a challenge. Taking a fluvial reservoir in the Bohai Sea as an example,and from the point of system engineering,the effect of polymer on produced liquid should be considered in the selection stage for polymer flooding. The influence law of different kinds of polymer on the simulated oil-water separation of crude oil is studied. The results show that the polymer with surface activity can greatly increase the treatment difficulty of oilfield produced water. Al- though the polymer without surface activity also can increase the stability of produced water,the in- crease level is low. Polymer has a small influence on the speed of oil-water separation,but it can seri- ously decrease the separation level of oil and water. Moreover,compared with the polymer with surface activity,the polymer without surface activity has a smaller influence on the separation level of oil and water. Based on the above results,it is suggested that linear polymer should be selected first as the poly- mer for oil displacement.